fix typo

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>

promql/promqltest/testdata/histograms.test

@@ -502,12 +502,12 @@ eval instant at 5m rate(const_histogram_bucket[5m])
 eval instant at 5m rate(const_histogram[5m])
     {} {{schema:-53 sum:0 count:0 custom_values:[0.0 1.0 2.0]}}
 
-# Zero buckets mean no observations, so there is no value that observations fall bellow,
+# Zero buckets mean no observations, so there is no value that observations fall below,
 # which means that any quantile is a NaN.
 eval instant at 5m histogram_quantile(1.0, sum by (le) (rate(const_histogram_bucket[5m])))
     {} NaN
 
-# Zero buckets mean no observations, so there is no value that observations fall bellow,
+# Zero buckets mean no observations, so there is no value that observations fall below,
 # which means that any quantile is a NaN.
 eval instant at 5m histogram_quantile(1.0, sum(rate(const_histogram[5m])))
     {} NaN

promql/promqltest/testdata/native_histograms.test

@@ -811,7 +811,7 @@ eval instant at 5m histogram_sum(rate(const_histogram[5m]))
 eval instant at 5m histogram_fraction(0.0, 1.0, rate(const_histogram[5m]))
     {} NaN
 
-# Zero buckets mean no observations, so there is no value that observations fall bellow,
+# Zero buckets mean no observations, so there is no value that observations fall below,
 # which means that any quantile is a NaN.
 eval instant at 5m histogram_quantile(1.0, rate(const_histogram[5m]))
     {} NaN